Sofa or armchair with adjustable sitting depth

ABSTRACT

A sofa or armchair with adjustable sitting depth (7-8), which has a back rest (1), which can be detached and taken off and the distance of which can be changed and thus, the sitting depth can be changed, and to which belongs an adjusting and locking device (2), with which a stepless or adjustment with steps are locked. E.g. the back of a sofa is traditionally fixed and almost all adjustment possibilities have been different solutions by cushions, which however, are not always satisfying when thinking of needs of different people. With this solution people of different lengths can adjust the sitting depth of a sofa or armchair fitting to themselves, which at the same time makes the sitting more comfortable and along with that reduces likelihood of back problems. Also the adjustable back rest gives new dimensions and possibilities for furniture design and product development.

FIELD OF THE INVENTION

The invention relates to a sofa or armchair with an adjustable backrestto accommodate people of differing height.

DESCRIPTION OF THE INVENTION

Various types of backrests are known, including:

A. fixed back rest;

B. the following methods or mechanisms: inclination of the back rest,support for the lumbar region of the back, moving of back high position,and lifting and inclining of the seat;

C. car seats and the like are fitted with equipment to move the wholeseat such as glide rails or the like;

D. office chairs can also have distance adjustment of the support forthe lumbar region of the back.

The known systems and methods for distance regulation of the back,mainly used in chairs, are not designed for use in couches, sofas andarmchairs and are therefore impossible or at least only with difficultyapplicable to sofas or armchairs. Furthermore, these systems are toocomplicated and troublesome to be used by children and the elderly. Tounfasten, to take off and remount the back of a sofa would be difficultor impossible.

SUMMARY OF THE INVENTION

An armchair or sofa with an adjustable sitting depth in accordance withthe invention has a simple construction and is easy to use. The back iseasy to take off and to place back, and the sitting depth adjustment issimple to effect.

After disconnecting the back it can be taken off and placed back simply,and then easily locked by moving the adjustment locking device intolocking position.

The invention makes it possible for people of different height to adjustthe back rest of their sofa to a position where the backrest gives thebest support to the back and keeps the sitting position comfortable,thus reducing for its part various back problems which result from a badsitting position.

The invention provides a new point of view for furniture design andmakes it possible to design a piece of furniture which is both practicaland versatile.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic side elevation view of a first embodiment of asofa or armchair in accordance with the invention with an adjustablesitting depth with a back rest and an adjusting and locking service.

FIG. 2 is a diagrammatic rear elevation view of a portion of theembodiment of FIG. 1 showing an end of the back rest--seen frombehind--and its adjusting and locking device here turned to the left.

FIG. 3 is like FIG. 2 but the adjusting and locking device is turned toits locking position as shown in FIG. 1.

FIGS. 4 and 5 are like FIGS. 2 and 3 and illustrate a second embodimentof an adjusting and locking device in accordance with the invention.

FIG. 6 is a diagrammatic rear elevation view of a portion of a sofa orarmchair illustrating a third embodiment of an adjusting and lockingdevice in accordance with the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows the end of a sofa or armchair--seen from the side--where 7is the sofa or armchair, 8 the end comprising of a lifting or armrestpart, 1 the back rest, with an adjusting and locking device 2 in itslocking position. When adjustment of the position of the backrest is tobe effected in predetermined steps, surfaces of locking device 2 andcorresponding surfaces of armrests 8 can be roughened at locations 9and/or 10 or provided at locations 9 and/or 10 with cogs, slots, pins orthe like in order to increase the locking effect of locking device 2. Inthe illustrated embodiment, cogs are provided on the upper surface ofarmrest 8 and on the corresponding upper surface of slot 3 in device 2.

FIG. 2 shows the back rest 1 from behind. The adjustable and lockingdevice 2 is fastened to the back with a hinge 6. The device 2 has alocking slot 3, which locks the adjustment when the device is turned onhinge 6 to its locking position. No. 5 points out the place where thereis a slot on the back rest which makes it possible to place the backdirectly down onto the armrests or to lift it up and remove the wholeback from the armrests.

FIG. 3 is the same as FIG. 2 but the adjusting and locking device 2 isshown turned on hinge 6 to the right to its locking position, with thelocking slot being clearly visible.

In the embodiment of FIGS. 4 and 5 the back rest 1 is of the same kindas in FIGS. 1-3, but the adjusting and locking device 2 is smaller andthe slot is replaced by a locking bolt or hook 4, or by a correspondingholder.

In lieu of the hinge mounting illustrated in FIGS. 1-5, the adjustingand locking device may be slidably mounted on backrest 1 such as on arail or in a slot on the backrest.

A suitable arrangement is shown in FIG. 6 in which the adjustablelocking device comprises a pin 11 which is movable along slot 12 inbackrest 1 between a locking position shown in phantom in which pin 11engages armrest 8, and disengaged position shown in full line in whichpin 11 is disengaged from armrest 8. A suitable arrangement is shown inFIG. 6 in which the adjustable locking device comprises a pin 11 whichis movable along slot 12 in backrest 1 between a locking position shownin phantom in which pin 11 engages armrest 8 and a disengaged positionshown in full line in which pin 11 is disengaged from armrest 8.

What is claimed is:
 1. In a sofa or armchair having armrests and abackrest, the improvement which comprises:a movable and adjustablelocking device mounted on each end of the backrest for adjusting thesitting depth of the backrest horizontally to accommodate people ofdiffering height; and means for mounting each of said adjustable lockingdevices on said backrest such that each adjustable locking is movablebetween a locking position in which said device engages said armrestsuch that said backrest is secured in a desired sitting depth positionand such that said backrest is prevented from being lifted off of saidarmrests, and a disengaged position in which said locking device isdisengaged from said armrest such that, when both of said adjustablelocking devices are in said disengaged position, said backrest can bemoved horizontally along said armrests to adjust said sitting depth ofthe backrest, and can be lifted off of or placed down on said armrests;each of said adjustable locking devices, after being moved into saidlocking position to locate said backrest in said desired sitting depthposition, engaging said armrest for locking the backrest in said desiredsitting depth position.
 2. A sofa or armchair according to claim 1wherein said mounting means comprises a hinge connecting the adjustablelocking device to said backrest whereby said adjustable locking deviceis turnable on said hinge between said locking and disengaged positions.3. A sofa or armchair according to claim 1 wherein said locking devicecomprises a member slidably mounted on said backrest for movementbetween said locking position and said disengaged position.
 4. A sofa orarmchair according to claim 1 wherein said armrest comprises means forincreasing the locking effect of said adjustable locking device forlocking the backrest in said desired sitting depth position.
 5. A sofaor armchair according to claim 4 wherein said locking effect increasingmeans comprises a form or shape on a surface of said arm rest which isengaged by said adjustable locking device when said adjustable lockingdevice is in said locking position.
 6. A sofa or armchair according toclaim 4 wherein said adjustable locking device comprises means forincreasing its locking effect for locking the backrest in said desiredsitting depth position.
 7. A sofa or armchair according to claim 6wherein said locking effect increasing means comprises a form or shapeof a surface of said adjustable locking device which engages saidarmrest when said adjustable locking device is in said locking position.8. A sofa or armchair according to claim 1 wherein said adjustablelocking device comprises means for increasing its locking effect forlocking the backrest in said desired sitting depth position.
 9. A sofaor armchair according to claim 8 wherein said locking effect increasingmeans comprises a form or shape of a surface of said adjustable lockingdevice which engages said armrest when said adjustable locking device isin said locking position.